GENEVA. September 23 (UNHCR) - The UN refugee agency on Tuesday said more than 138,000 refugees, mainly ethnic Kurds fleeing militant threats to towns and villages in northern Syria, have crossed into southern Turkey since Friday.

The latest arrivals passed through the two remaining open border points at Yumurtalik and the crossing east of Murstipinar/Akmanak.

UNHCR spokesperson Melissa Fleming said the Turkish authorities had told the refugee agency that they are now managing the entry of refugees through two border points (previously nine) in three phases: security checks in order to maintain the civilian character of asylum; health checks, including measles and polio vaccination for very young children; and registration.

Mobile registration centres, large trucks donated by UNHCR and complete with computers, biometric and photographic equipment, are operating in the border crossing of Yumurtalik and in the yard of a primary school of Namik Kemal, Suruc.

Registration is also being carried out by government officials at a boarding school in Onbirnisan, in Suruc district hosting an estimated 50,000 refugees, as well as the Suruc town centre - less than 15 kilometres from the Syrian border.

Once registered, refugees receive an ID card, which provides access to free health care services in Turkish clinics, as well as other aid provided by local municipalities, non-governmental organizations and other aid agencies. The card is a critical document that also shows refugees have the temporary protection of the Turkish government.

"UNHCR field staff are visiting the border areas and areas hosting refugees on a daily basis, assessing urgent needs and coordinating the response among other humanitarian actors," Fleming said.

"Our field staff report the majority of new arrivals are women, children and the elderly, who arrive exhausted having walked several kilometres to safety on a dusty, rough road, with their luggage. Some of the elderly and disabled are carried to safety by relatives, their wheel chairs hopelessly unsuited to the rough terrain," she added.

On arrival, the refugees are given water before being transported to a registration point. The Turkish Red Crescent has set up a medical observation tent for injured refugees and more than 290 Syrians were taken to the Suruc hospital by ambulances over the weekend.

The refugee agency has already provided tens of thousands of relief items - blankets, sleeping mats, jerry cans and plastic sheets - to help in the response, coordinated by the government of Turkey. More aid is on the way.

UNHCR's Fleming said the first in a series of airlifts bringing aid for up to 200,000 people is expected to arrive in Turkey, from Amman, Jordan, on Wednesday afternoon. Another three flights from Amman and Copenhagen are expected to follow later in the week.

Many refugees are sheltering with relatives and friends, while others are staying in schools, wedding halls, mosques or other buildings. The Turkish government has set up two transit centres for 10,000 people each at Suleymansah Park in Mursitpinar and Onbirnisan, in Suruc, with support from UNHCR. The government also continues its work on two new camps already under way - Derik Camp in Mardin and Islahiye camp - also with UNHCR support.